XP 
C  3 


Press  Bulletin  Series  Issue<1  Twice  QuartepIy 

STATE  OF  ILLINOIS  -   0^ 

DEPARTMENT  OF  REGISTRATION  AND  EDUCATION  , 

A.  M.  SHELTON.  Director  I    C> 

DIVISION  OF  THE  %*\£^    O  < 

STATE  GEOLOGICAL  SUR VE Y  ^>\  xa\^  \*>  'v 

M.  M.  LEIGHTON,  Chief,  Urbana  C^>*    ~£\ 


No  15  ILLINOIS  PETROLEUM 


May  12,  1928 


CONTENTS 

PAGE 

A  study  of  the  core  of  the  Yanaway  well  No.  33  in  the  Siggins  pool l 

Corrosion  in  the  Eastern  Illinois  oil  fields 9 

A  STUDY  OF  THE  CORE  OF  THE  YANAWAY  WELL  NO.  33  IN 

THE  SIGGINS  POOL 

By  J.  E.  Lamar 

Introduction 

As  the  amount  of  oil  in  Illinois  which  can  be  produced  economically 
by  pumping  decreases,  the  application  of  methods  for  increasing  recovery 
becomes  necessary  in  order  to  avert  a  premature  abandonment  of  many 
pools  and  consequent  loss  of  a  large  amount  of  recoverable  oil.  However, 
the  intelligent  application  of  improved  recovery  methods  requires  specific 
information  concerning  the  oil  sands,  their  detailed  character,  and  their 
vertical  and  horizontal  extent.  Unfortunately  such  data  are  not  generally 
obtainable  from  the  available  records,  most  of  which  are  all  too  brief. 
Core  drilling  is  therefore  advisable  in  any  attempt  to  determine  if  the  amount 
of  oil  remaining  in  the  sand  is  sufficient  to  warrant  improved  recovery 
methods  and  whether  or  not  other  conditions  are  right  for  the  successful 
application  of  mining,  flooding,  or  repressuring  in  any  given  pool.  The  pur- 
pose of  this  paper  is  to  indicate  the  type  of  information  which  may  be  ob- 
tained from  a  single  core  and  to  show  its  bearing  on  deductions  concerning 
some  of  the  items  mentioned  above.  The  Petroleum  Engineering  Section 
of  the  Illinois  State  Geological  Survey  is  prepared  to  make  similar  studies 
in  other  fields  of  the  State,  wherever  satisfactory  core  samples  are  avail- 
able. 

Location 

The  Yanaway  well  No.  33  is  located  in  the  SW.  %  SE.  %  sec.  1, 
T.  10  N.,  R.  10  E.,  in  the  north  part  of  the  Siggins  pool  in  northeastern 
Cumberland  Count}-.  This  pool  appears  to  be  one  of  the  most  promising  in 
the  State  for  the  application  of  mining  methods  of  oil  recovery.  For  this 
reason    detailed    information    on    sand    conditions    and    character    should    be 


^  ILLINOIS  PETROLEUM 

valuable  in  deciding  how  mining  can  be  best  applied.  Though  the  Yanaway 
No.  33  is  technically  an  edge  well,  the  data  from  it  are  thought  to  be  not 
unlike  those  of  the  rest  of  the  pool  in  the  major  features. 

Method  of  Coking  and  Sampling. 

The  core  of  the  sand  of  the  Yanaway  well  was  obtained  with  a  core 
bit  for  cable  tools  furnished  by  the  Keystone  Driller  Company  of  Joplin. 
Missouri.  The  Ohio  Oil  Company  arranged  with  the  Illinois  Geological 
Survey  for  collecting  and  studying  samples  of  core  from  practically  every 
foot  of  the  sand. 

The  samples  of  core  thought  to  be  oil  sand  were  removed  from  the 
core  barrel,  rinsed  rapidly  in  water  to  remove  the  mud  usually  coating  them, 
wrapped  in  wax  paper  and  sealed  by  immersing  in  melted  paraffin.  Other 
samples  were  similarly  wrapped  but  not  in  all  instances  immediately  after 
being  taken  from  the  core  barrel.  Laboratory'  studies  of  the  core  were 
made  along  the  four  following  lines:  (1)  description  of  core  samples,  (2) 
oil  content,  (3)  porosity,  and  (4)  texture.  This  work  was  largely  done 
by  C.  R.  Clark. 

Studies  of  the  Core 
description  of  samples 
The  samples  of  core  were  examined   under  the  microscope   and   iden- 
tified as   to  kind   and   character  of   rock.      The   log   of   the   sand   is   given 
below  and  is  shown  graphically  in  figure  1. 

Log  of  Yanaway  well  No.  33,  Ohio  Oil  Company 


Shale,  plastic,  light  gray-green 

Sandstone,     gray,     clayey,     interbedded 

with  gray  siltstone  and  some  shale; 

basal  3  feet  limy 

Sandstone,  medium-grained,  buff -gray.  . 
Shale,     gray,     bluish-gray     and     brown, 

carbonaceous,     broken     by     siltstone; 

splits  into  thin   flakes 

Coal    

Shale,    gray    or    greenish-gray;    soft    at 

top,  hard  at  bottom;  mostly  sandy... 
Sandstone,  light  gray,  fine-  to  medium- 
grained    

Shale,     dark     gray,     splits     into     thin 

flakes;    moderately  hard 

Coal    

Shale,  plastic,  gray,  moderately  hard.. 
Coal    


Thickness 

From 

To 

Feet. 

Feet 

Feet 
400% 

13% 

400  % 

414 

14 

414 

428 

44 

428 

472 

1 

472 

473 

17 

473 

490 

10 

490 

500 

4 

500 

504 

1 

504 

505 

1 

505 

506 

2 

506 

508 

ILLINOIS  STATE  GEOLOGICAL  SURVEY 


3  3051  00005  1304 


A    STUD'S   OF   THE   CORE   OF    VAN  AWAY    WELL    NO.    ■'<'■'>  3 

Shale    and    siltstone    interbedded,    gray, 

bluish-gray    and    greenish-gray;     soft 

in    upper    part;    hard,    sandy,    locally 

limy  in  basal  IS  feet 41  508  549 

Coal    2  549  551 

Shale,  gray,  greenish-gray  and  bluish- 
gray,    locally    sandy    or    limy;     basal 

portion  contains  plant  fossils 15  551  566 

Coal    8  566  574 

Shale,  gray,  hard,  sandy  to  very  sandy; 

contains  plant  fossils 7  574  581 

Sandstone,   gray,   dense,   hard 5  581  586 

Shale  and  siltstone  interbedded,  gray  or 

bluish-gray;    locally    sandy,    coaly    or 

limy    8  586  594 

Siltstone,     bluish-gray,     hard,     clayey; 

splits  into  thin   flakes 13  594  607 

Shale,  bluish-gray,  gritty 3  607  610 

Siltstone,    light    gray,    clayey,    middle 

foot  limy 3  610  613 

Shale,   bluish-gray,   hard 5  613  618 

The  term  siltstone  used  in  the  above  log  is  used  to  describe  those  sedi- 
ments composed  dominantly  of  fine  gritty  particles,  too  fine  to  be  called 
sand  and  too  coarse  to  be  called  shale.  Inasmuch  as  siltstones  ordinarily  con- 
tain a  high  percentage  of  clay  their  effect  on  oil  accumulation  and  migration 
is  similar  to  that  of  shale. 

OIL    CONTENT    OK     PER    CENT    OF    SATURATION 

The  oil  content  was  determined  as  the  difference  in  weight  of  a  sam- 
ple before  and  after  the  oil  had  been  removed  by  means  of  a  Soxhlet  ex- 
tractor— an  apparatus  especially  designed  for  removing  oils  from  solids. 
The  graphs  of  per  cent  saturation  given  in  figure  1  are  thought  to  be  mis- 
leading for  three  reasons.  (  1  )  Despite  the  fact  that  the  core  barrel  of  the 
bit  was  supposed  to  have  been  on  bottom  at  all  times,  the  way  in  which  the 
core  was  broken  in  the  barrel  suggested  that  it  had  been  raised  from  the  bot- 
tom of  the  hole  frequently  during  drilling.  This  would  permit  the  escape  of 
oil  from  the  core.  (2)  the  rate  of  drilling  with  the  core  bit  was  compara- 
tively slow  and  there  was  therefore  time  for  a  considerable  proportion  of  the 
oil  included  in  the  core  to  have  escaped.  Some  biscuits  of  core  bubbled  gas 
and  oil  after  removal  from  the  core  barrel  and  there  is  no  reason  to  suppose 
this  had  not  also  been  happening  while  the  core  was  in  the  core  barrel.  (.'5) 
Some  of  the  core  was  in  complete  or  partial  contact  with  the  mixture  of  oil 
and  water  in  the  hole,  which  afforded  opportunity  for  oil  to  penetrate  cracks 
or  fractures  in  the  core  The  oil  content  of  some  of  the  shale  samples  is 
thought  to  be  of  this  nature. 


4  ILLINOIS  PETROLEUM 

POROSITY 

The  porosity  was  determined  by  extracting  the  oil  from  the  sample  of 
core  and  then  measuring  the  volume  of  fluid  which  it  displaced  when  satur- 
ated. This  gave  the  volume  of  the  sample  with  the  pores  filled.  The  sample 
was  then  crushed  and  the  volume  of  the  resulting  grains  measured  by  deter- 
mining the  amount  of  fluid  they  displaced.  The  porosity  was  calculated  as 
follows : 

(Vol.  original  sample)  —  (Vol.  sand  grains)    X    100 

Per  cent  porosity  = ■ 

(Vol.  original  sample) 

TEXTURE 

The  texture  of  a  number  of  selected  samples  was  determined  by  making 
sieve  analyses  of  them.  The  clay  recorded  in  figure  1  is  the  material  which 
had  not  settled  through  15  inches  of  water  in  10  minutes.  The  other  grade 
sizes  were  determined  on  Tyler  Standard  Screen  Scale  sieves. 

Interpretation  of  Results  of  Tests 
general  sand  conditions 
significance  of  siltstones 
One  of  the  important  facts  brought  out  by  the  study  of  the  Yanaway 
core  is  the  existence  of  siltstone  as  distinct  individual  beds  and  as  "breaks" 
within  the  major  sand-bodies.     By  reason  of  their  intermediate  character  be- 
tween sandstone  and  shale,  siltstones  frequently  grade  laterally,  in  compara- 
tively short  distances,  into  either  sandstone  or  shale.     It  is  possible  therefore 
that  the  siltstones  of  the  Yanaway  No.  33  may  be  sandstone  or  shale  in  other 
wells  of  the  Siggins  pool.     It  is  thought  that  this  phenomenon  probably  ac- 
counts for  the  variation  in  the  thickness  of  the  producing  sands  in  different 
parts  of  the  field  and  may  also  indicate  why  as  many  as  six  oil  sands  are 
reported  in  some  wells. 

OIL-SAND    HOIUZONS 

The  log  given  in  figure  1  and  on  preceding  pages  suggests  that  in  the 
northern  part  of  the  Siggins  pool  there  are  five  horizons  where  sands  may 
be  expected  to  occur,  as  follows :  ( 1  )  the  upper  sand  found  from  400^2  to 
428  feet;  (2)  the  siltstone  horizon  from  447  to  450  feet;  (3)  the  middle 
sand  from  490  to  500  feet;  (4)  the  siltstone  zone  from  515  to  531  feet;  and 
(5)  the  lower  sand  and  siltstone  zone  from  581  to  613  feet.  Of  these  the 
second  is  thought  to  be  of  the  least  importance  as  a  possible  sand  horizon. 
The  frequent  changes  in  the  character  of  the  formations  in  the  lower  118  feet 
of  the  well  indicate  unstable  conditions  of  deposition  in  the  sea  in  which  these 
sediments  were  laid  down,  and  consequently  lateral  variations  in  the  sand- 
stones and  siltstones  of  the  lower  118  feet  of  the  Siggins  sand  will  probably 
be  found  to  be  greater  and  more  abrupt  than  in  the  upper  100  feet. 


A    STUDY   OF   THE   CORE   OF   YAN.VWAY    WELL   NO.    33 


I  m  m  m  it 


it 


?*. 


ILLINOIS  PETROLEUM 


THICKNESS   OF  OIL   SANDS 


It  the  thickness  of  the  sandstones  found  in  the  core  of  the  Yanaway  No. 
33  be  used  as  criteria,  the  sand  records  available  for  many  of  the  wells  in 
the  Siggins  pool  are  misleading  in  that  they  show  far  too  great  a  thickness 
of  sand.  It  is  obvious  that  not  all  the  formations  logged  as  sand  were  pro- 
ductive of  oil,  but  the  records  fail  to  indicate  how  thick  the  sand  bodies  are 
and  at  what  depth  they  were  found.  Sand  records  at  hand  show  from  18 
to  91  feet  of  upper  sand,  but  it  is  doubtful  if  the  91-foot  thickness  recorded 
was  actually  all  sand.  More  probably,  the  sediments  logged  as  sand  were  the 
upper  sandstone  and  a  series  of  interbedded  shales  and  sandstones  lying  be- 
low. In  the  case  of  the  lS-foot  sandstone  it  would  appear  that  some  of  the 
upper  part  of  the  upper  sand  of  the  Yanaway  No.  33  grades  laterally  into 
shale. 

SEDIMENTARY    STRUCTURES    IN    THE    SANDSTONES    AND    SILTSTONES 

Judging  by  the  manner  in  which  the  core  broke,  the  three  sands  are  all 
thin-bedded,  in  layers  from  !<4  inch  to  2  inches  thick.  The  bedding  planes 
are  irregular  and  many  of  them  have  thin  films  of  highly  micaceous  clay  coat- 
ing them.  Several  pieces  of  core  were  cross-bedded.  The  siltstones  are  even 
more  irregularly  heckled  than  the  sandstones  and  arc  usually  very  thin- 
bedded,  resembling  shale. 

THE  UPPER   SAND 
INTRODUCTION 

Since  the  upper  sandstone  is  the  most  important  in  the  Siggins  pool  and 
is  the  sand  on  which  improved  recovery  methods  would  most  logically  be 
applied,  it  is  discussed  in  detail.  The  general  lithologic  characteristics  ex- 
hibited by  the  upper  sandstone  are  also  present  in  the  two  lower  sands. 

OCCURRENCE    (IF    OIL 

Examination  of  the  core  of  the  upper  sand  as  it  came  from  the  core 
barrel  showed  that  the  oil  in  it  was  not  uniformly  distributed.  This  is 
further  borne  out  by  the  per  cent  saturation  of  the  core  samples  (fig.  1) 
which  show,  considering  only  the  outstanding  features,  an  irregular  arrange- 
ment of  the  points  of  high  and  low  saturation,  although  in  general  the  lower 
portion  is  shown  to  have  a  higher  saturation  than  the  upper. 

Some  pieces  of  core  showed  even  more  restricted  localization  of  the 
oil  than  indicated  above,  for  in  many  of  them  by  far  the  greatest  amount 
of  oil  was  found  in  a  thin  streak  of  coarse  and  apparently  very  porous 
sandstone  which  varied  from  ]/%  to  }4  of  an  inch  in  thickness.  The  cementa- 
tion of  this  coarse  sandstone  was  much  less  firm  than  that  elsewhere,  inas- 
much as  the  core  commonly  broke  along  the  coarser  bands. 


A    STUDY   OF   T11K   CORE   OF   YANAWAY    WELL    NO.    :'>•">  7 

II  vina:  OF  THE  SAND 

The  texture  of  parts  of  the  three  sandstones  in  the  Yanaway  No.  33 
well  are  shown  graphically  in  figure  1.  In  general  it  may  he  said  that  all 
the  sandstones  are  fine-grained  and  that  all  have  a  high  clay  content,  ex- 
cepting sample  I).  The  clay  is  present  as  a  rilling  between  the  sand  grains. 
Sample  A  is  high  in  very  hue  sand  as  might  be  expected  from  its  position 
immediately  below  a  shale.  The  siltstone  "breaks"  of  the  upper  sand  are 
shown  in  graphs  B  and  C,  with  their  high  per  cent  of  clay  and  material 
passing  a  150-mesh  screen.  Graphs  D,  E,  F,  and  G  indicate  the  texture 
of  the  main  body  of  the  upper  sand. 

The  middle  sand,  illustrated  by  Graph  H,  is  the  coarsest  of  any  of  the 
sands  tested.  The  lower  sand  is  very  fine-grained,  high  in  clay  and  ma- 
terial passing  a  150-mesh  sieve,  and  approaches  a  siltstone  in  composition 
as  shown  by  Graph  J. 

POROSITY' 
DISTRIBUTION 

The  results  of  the  porosity  determinations  on  samples  of  the  sand- 
stones and  siltstones  are  shown  in  figure  1.  The  porosity  determinations 
as  a  rule  serve  to  distinguish  between  the  siltstones  and  sandstones,  the 
former  being  much  less  porous  than  the  latter.  The  upper  sand  shows 
considerable  variation  in  porosity,  doubtless  due  to  variations  in  the  tex- 
ture of  the  sandstone.  The  middle  and  lower  sands  have  comparatively 
uniform  porosities. 

RELATION    OF    CLAY    CONTENT    TO    POROSITY 

It  has  been  previously  suggested  that  the  clay  present  in  the  sands  of 
the  Yanaway  No.  33  well  fills  the  spaces  between  the  sand  grains  and  there- 
by reduces  the  porosity  of  the  sandstones.  This  statement  is  borne  out  by 
data  shown  in  figure  1.  Graphs  of  texture  show  a  high  clay  content  for 
samples  B  and  C.  The  porosity  is  low.  Samples  I),  E,  and  F  show  de- 
creasing porosity  and  increasing  clay  content.  Sample  H  is.  in  a  way, 
an  exception.  Both  its  clay  content  and  porosity  are  comparatively  high, 
but  this  is  because  it  has  so  much  medium-grained  sand  that  the  pores 
are  larger  and  the  amount  of  fine  material  present  is  insufficient  to  fill  the 
pores  as  completely  as  it  dues  in  the  other  samples. 

RECOVERABLE   OIL 

Inasmuch  as  the  Yanaway  No.  33  is  an  edge  well,  the  saturation  of 
the  sands  is  doubtless  lower  than  that  of  the  sand  in  the  more  productive 
portion  of  the  Siggins  pool.  However,  assuming  an  average  saturation 
of  only  '■]  per  cent,  which  is  probably  a  conservative  estimate  of  the  actual 
saturation  of  the  upper  sandstone  in  the  Yanaway  No.  33,  and  a  60  per 
cent  recovery  of  the  oil  remaining,  the  production  would  still  be  over  2,100 
barrels  per  acre  for  the  upper  sand.     This  figure  is  essentially  an  estimate. 


5  ILLINOIS   l'KTROLKUM 

yet  it  is  significant  of  the  larger  recovery  which  may  he  anticipated  for  other 
parts  of  the  pool. 

Summary   and   Bearing   of   Studies   on   Improved   Recovery    Methods 

The  study  of  the  core  of  Yanaway  No.  33  alone,  does  not  yield  defi- 
nite data  on  the  advisability  of  mining,  flooding,  or  repressuring  in  the  Sig- 
gins  pool,  but  it  nevertheless  indicates  certain  factors  which  must  be  con- 
sidered before  improved  methods  are  applied.  These  factors  are  as  fol- 
lows : 

(1)  Three  sands  which  contain  oil  are  present  in  the  northern  part  of  the 
pool  in  which  the  Yanaway  No.  33  is  located. 

(2)  Two  siltstone  horizons  are  present;  these  may  be  sandstone  elsewhere 
in  the  Siggins  pool. 

(3)  The  sands  of  the  Siggins  pool  are  probably  lenticular  and  therefore  a 
thorough  study  of  sand  records,  supplemented  by  core  drilling,  should  be  made  to 
outline  in  detail  the  major  sand  bodies. 

(4)  Of  the  three  sands  present  the  upper  is  the  thickest  and  probably 
contains  the  most  oil.  It  is  therefore  the  most  logical  sand  body  for  the  applica- 
tion of  improved  recovery  methods. 

(5)  The  upper  sandstone  is  fine-grained  and  lies  in  thin,  irregular  beds. 
There  are  shale  and  siltstone  "breaks,"  particularly  in  the  upper  part  of  the 
sandstone. 

(6)  The  porosity  of  the  sandstone  portions  of  the  upper  sand  varies  from  8 
to  23  per  cent. 

(7)  The  average  saturation  of  the  sandstone  beds  of  the  upper  sand  is  2.2 
per  cent.  This  is  thought  to  be  too  low  because  of  a  probable  loss  of  oil  from  the 
core  samples. 

(8)  Assuming  60  per  cent  recovery  of  the  oil  now  in  the  upper  sand  and  3 
per  cent  saturation,  there  are  about  2100  barrels  of  recoverable  oil  per  acre. 


CORROSION   IX    THE  EASTERN   ILLINOIS  OIL  FIELDS 

By  J.  E.  Lamar  and  C.  R.  Clark 

Introduction 

The  general  problem  of  corrosion  is  of  such  great  industrial  import- 
ance that  the  reports  on  various  phases  of  the  subject  comprise  a  voluminous 
literature'  Corrosion  of  the  metallic  equipment  used  in  the  business  of 
producing  oil  and  gas  is  a  special  phase  of  the  corrosion  problem,  which, 
because  of  its  economic  importance  to  the  petroleum  industry,  has  been 
the  subject  of  special  studies.-'  The  work  thus  far  reported  has  been  either 
of  a  general  nature  or  else  has  had  particular  application  to  problems  other 
than  those  confronting  the  Illinois  oil  operators.  Therefore,  the  Petroleum 
Engineering  section  of  the  Illinois  Geological  Survey  undertook  a  series 
of  held  investigations  in  the  eastern  Illinois  oil  fields  in  order  to  determine 
the  causes  of  oil-field  corrosion  more  precisely,  so  that  any  remedies  avail- 
able might  be  applied.  The  purpose  of  this  report  is  to  make  the  results 
of  the  investigation  available  to  oil  operators. 

General,  systematic  studies  of  the  waters  in  the  Illinois  oil  fields  were 
begun  by  the  Illinois  Geological  Survey  in  1924.  One  of  the  problems  con- 
sidered in  this  investigation  was  the  possibility  of  determining  the  relative 
corrosiveness  of  oil-field  waters  by  comparing  analyses  of  the  mineral  mat- 
ter dissolved  in  them.  Although  these  investigations  are  not  yet  completed, 
it  has  been  concluded  that  the  relative  corrosiveness  of  waters  cannot  be 
determined  on   the   basis   of   a   chemical   analysis. ';' 

The  new  work  undertaken  by  the  Petroleum  Engineering  section  con- 
sisted principally  of  a  more  extensive  determination  of  two  of  the  chemical 
properties  of  the  oil-field  waters  :  (  1  )  the  relative  acidity,  and  (  2  )  the  hydro- 
gen sulfide  content.  Quantitative  determination  of  these  properties  was 
undertaken  in  the  eastern  Illinois  oil  fields  during  the  summer  of  1927, 
and  an  attempt  was  made  to  correlate  the  results  of  these  tests  with  the 
relative  corrosiveness  of  the  waters. 

(  )ne  of  the  outstanding  difficulties  in  the  study  of  oil-field  corrosion 
problems  was  the  absence  of  any  comparable  data  by  which  the  rate  of 
corrosion  could  be  determined.  Comparison  of  corrosion  in  wells  in  indi- 
vidual pools  or  districts  was  [airly  satisfactory,  for  the  judgment  of  field 
superintendents  who  were  familiar  with  operating  conditions  over  such 
areas  could  be  relied  upon  to  classify  the  waters  in  a  general  way.  No  quan- 
titative determinations  of  the  rate  of  corrosion  could  be  made,  however, 
so  the  terms  "corrosive',  "slightly  corrosive"  and  the  like,  as  used  in   ibis 


1  For  a  comprehensive  bibliography  on  the  general  subject  of  corrosion,  see  Speller, 
1-'.  X..  Corrosion,  pp.  565-577,  McGraw-Hill   Book  Co.,  New   York,   1925. 

-.Mills.  U.  Van  A.,  Protection  of  oil  field  equipment  from  corrosion,  U.  S.  Bureau 
of   .Mints   Hull,   -i:',:;,    1925. 

1  Moulton,  Gail    !•'..    Illinois  State  Geol.   Survey,  personal  communication. 


10  ILLINOIS  PETKOLEUM 

report,  are  definitely  significant  only  of  the  relative  corrosiveness  in  the 
specific  field  under  discussion.  In  comparing  fields  as  units,  the  state- 
ments regarding  corrosiveness  are  the  concensus  of  opinion  of  a  large 
number  of  oil  men. 

Acknowledgments 
The  writers  wish  to  express  their  appreciation  to  the  many  members 
of  the  petroleum  industry  of  Illinois  for  their  assistance  and  advice  in  mat- 
ters pertaining  to  this  investigation,  and  to  the  State  Water  Survey  for 
their  valuable  cooperation  in  making  the  chemical  analyses  of  the  samples 
of  oil-field  waters.  Gail  F.  Moulton's  constructive  criticism  of  the  manu- 
script has  also  been  valuable. 

Conclusions  and  Suggestions 
.  From  the  subsequent  detailed  description  of  corrosion  in  the  south- 
eastern Illinois  oil  fields  it  is  evident  that  the  oil-field  brines  are  responsible 
for  the  corrosion  of  the  oil  field  equipment.  Although  no  chemical  charac- 
teristics of  the  brines  are  clearly  responsible  for  their  corrosive  action,  in 
the  majority  of  cases  it  appears  that  the  action  of  hydrogen  sulfide,  both 
as  a  gas  and  in  solution,  is  the  most  important  single  factor. 

Remedies  for  corrosion  might  be  found  in  the  use  of  materials  which 
would  resist  the  action  of  the  waters.  On  account  of  the  large  amount  of 
equipment  required  for  each  well,  the  number  of  alloys  and  metallic  coat- 
ings which  might  be  used  is  restricted  by  the  necessity  of  low  cost,  and  it 
is  probable  that  not  many  alloys  or  coatings  remain  untried.  The  solution 
of  the  problem  would  therefore  seem  to  lie  along  some  other  line. 

Corrosion  caused  by  waters  which  may  be  shut  out  of  the  wells  by  use 
of  casing  is  easily  controlled.  In  such  a  well  the  use  of  fluid  mud,  cement, 
or  oil,  behind  the  casing  to  protect  it  from  contact  with  water  should  extend 
the  life  of  the  casing  beyond  the  life  of  production.  In  certain  parts  of 
Illinois  oil  field  work  of  this  type  should  be  very  profitable. 

There  is  little  doubt  that  the  water  produced  with  the  oil  and  which 
causes  so  much  of  the  corrosion  can  be  reduced  in  many  places  and  en- 
tirely eliminated  in  a  few  of  them.  The  amount  of  water  produced  has 
been  observed  to  bear  ^uch  a  close  relation  to  the  rate  of  corrosion  that 
it  seems  apparent  that  even  a  reduction  in  the  amount  of  water  handled 
with  the  oil  would  retard  the  rate  of  corrosion.  The  mudding  oft"  of  cor- 
rosive waters  and  cementing  off  of  bottom  waters  in  the  Flat  Rock  pool, 
undertaken  in  1918  by  the  State  Geological  Survey  in  cooperation  with 
the  operators,  is  a  good  example  of  the  type  of  repair  work  which  may  be 
done  to  reduce  corrosion  over  some  parts  of  the  eastern  oil  fields.  The  work 
in  the  Flat  Rock  pool,  Crawford  County,  resulted  in  satisfactory  repairs 
on  ten  wells.*     The  net  result  was  that  an  average  increase  of  six  barrels 


4  Tough,  Fred  B.,  Williston,  Samuel  H.,  and  Savage,  T.  E.,  Experiments  in  water 
control  in  the  Flat  Rock  pool,  Crawford  County;  Illiirois  State  Geol.  Survey  Bull.  40, 
pp.    97-140,    1919. 


CORROSION    IN"   EASTERN    ILLINOIS  OIL  FIELDS  11 

per  day  per  well  was  obtained  at  an  average  oust  of  -tlifil  per  well.  It  is 
difficult  to  measure  the  additional  benefit  from  reduction  in  the  amount  ol 
salt  water  handled,  and  therefore  reduced  lifting  costs,  as  well  as  slower 
rates  of  corrosion,  but  the  increased  yield  of  oil  more  than  paid  the  cost 
of  the  work. 

Systematic  petroleum  engineering  studies  of  other  parts  of  the  Illi- 
nois oil  fields  to  determine  the  feasibility  of  similar  repair  work  are  justified 
by  the  results  obtained  in  the  work  of  1918.  Areas  in  which  corrosion  is 
very  serious  are  particularly  promising  of  financial  gain  from  this  sort  of  re- 
pair work  because  of  the  saving  to  be  expected  from  fewer  replacements 
of  pumping"  equipment. 

In  anticipation  of  undertaking  cooperation  in  well  repair  work  the  Pe- 
troleum Engineering  section  of  the  Illinois  Geological  Survey  has  con- 
ducted experimental  laboratory  studies  on  the  setting  of  cements  under 
various  conditions,  and  on  the  preparation  of  fluid  muds  which  will  stay 
in  suspension  for  long  periods  of  time.  The  results  of  these  investigations 
will  be  published  in  later  reports.  Requests  for  cooperation  in  the  solu- 
tion of  water,  cementing,  mudding.  and  other  problems  in  the  field  of 
petroleum  engineering  will   be  cordially  received. 

The  remainder  of  the  paper  is  devoted  to  a  detailed  discussion  of  the 
types  of  corrosion,  the  relation  of  the  chemical  composition  of  oil-field 
brines  to  corrosion,  the  importance  of  hydrogen  sulfide  in  corrosion,  sub- 
stances that  accelerate  corrosion,  the  effect  of  corrosion  on  different  mater- 
ials used  in  oil  well  equipment  and  details  of  corrosion  in  the  various  oil 
fields  of  eastern  Illinois. 

Types  of  Corrosion 

introduction 
There  are  two  important  types  of  corrosion  which  do  serious  damage 
to  oil-field  equipment:  (1)  soil  corrosion,  which  affects  equipment  buried 
in  the  soil,  and  12)  corrosion  by  oil-field  brines  and  associated  gases.  Still 
another  type,  atmospheric  corrosion  or  rusting,  is  also  present,  but  as  it  is 
much  slower  and  is  comparatively  easy  to  control,  it  is  not  discussed  here. 

SOIL    CORROSION 

Soil  corrosion  has  been  ascribed  to  an  "acid"  condition  of  the  soil,  but 
it  is  doubtful  if  this  is  generally  the  cause.  Only  in  swampy  and  peaty 
soil.-  i>  acid  present  in  sufficiently  large  amounts  to  markedly  increase 
the  ordinary  rate  of  soil  corrosion.  Many  soils  give  an  acid  reaction  if 
tested  with  an  ordinary  indicator  like  litmus,  because  the  basic  color  of 
the  litmus  is  adsorbed  by  the  colloidal  matter  in  the  soil.  Thus  many  soils 
have  been  classified  as  true  acid  soils  when  in  reality  they  possess  only  "ap- 
parent acidity." 


12  ILLINOIS  PETROLEUM 

Corrosion  which  affects  buried  equipment  is  the  result  of  an  electro- 
chemical reaction  between  the  metallic  equipment  and  soil  water  containing 
dissolved  salts,  and  gases.  That  water  is  essential  is  evidenced  by  the  fact 
that  equipment  buried  in  soil  containing  little  or  no  moisture  is  not  subject 
to  soil  corrosion. 

Soil  corrosion  may  be  minimized  by  the  application  of  various  pro- 
tective paints  or  coatings,  either  asphaltic  or  galvanized.  In  order  to  be 
effective  these  coatings  must  be  moisture-proof.  Great  care  should  be  ex- 
ercised, therefore,  to  prevent  cracking  or  chipping  of  the  coating  during 
handling  and  installing,  for  the  protective  seal  must  remain  intact  over  the 
whole  piece  or  much  of  its  effectiveness  will  be  lost. 

WATER    AND    GAS    CORROSION 

Corrosion  by  oil-field  brines  and  gases  may  affect  any  of  the  subsurface 
or  surface  equipment  with  which  they  come  in  contact — casing,  tubing, 
sucker  rods,  lead  lines,  vacuum  lines,  condensers,  and  the  like,  all  are  sub- 
ject to  corrosion  in  some  places.  Not  only  is  metallic  equipment  eaten  away 
but  also  locally  there  is  deposited  contemporaneously  a  scale,  usually  largely 
composed  of  iron  salts  and  sulfur,  which  often  fills  lead  lines  and  vacuum 
lines  to  such  an  extent  that  they  must  be  replaced. 

Generally  the  worst  corrosion  is  caused  by  bottom-  or  edge-waters. 
Other  corrosive  waters  penetrated  in  drilling  can  be  shut  off  by  strings  of 
casing  which  may  be  mudded  or  cemented. 

Water  and  gas  corrosion  are.  like  soil  corrosion,  electro-chemical  in 
their  action.  The  rate  of  corrosion  is  governed  largely  by  three  factors  : 
(1)  the  chemical  composition  of  the  oil-field  brine,  (2)  the  presence  or  ab- 
sence of  products  of  corrosion  that  may  accelerate  or  retard  corrosion, 
and  (3)  the  character  of  the  materials  from  which  the  oil-field  equipment 
is  made.     These  matters  are  considered   in  the  above  order  in  this  report. 

Relation  of  Chemical  Composition  of  Oil-Field  Brines  to  Corrosion 
choice  of  wells  for  investigation 
Because  of  the  impossibility  of  securing  comparable  data  on  the  rate 
of  corrosion,  the  selection  of  corrosive  and  noncorrosive  waters  for  study 
was  of  necessity  confined  to  groups  of  contrasting  samples  from  individual 
pools.  Waters  from  two  different  areas  were  chosen  for  study,  the  Parker 
Township  pool  in  Clark  County  and  the  Bridgeport  pool  in  Lawrence 
County.  These  areas  were  favorable  for  sampling  because  in  both  pools 
there  are  wells  producing  from  the  same  sands  and  in  close  proximity  to 
each  other,  some  of  which  yield  corrosive  water  and  others  noncorrosive 
water.  The  wells  selected  were  known  to  be  producing  regularly  and  to 
be  in  good  condition.  By  sampling  in  this  way  it  was  believed  that  the 
analyses  of  the  corrosive  and  noncorrosive   waters  in  each  area  could  be 


CORROSION    IN    EASTERN    ILLINOIS   (III     FIELDS  13 

accurately  compared  to  determine  what  relationship  if  any,  the  chemical 
composition  of  the  waters  might  bear  to  corrosion. 

Three  water  samples  were  taken  in  the  northern  part  of  the  Parker 
Township  pool.  Two  were  from  wells  in  which  corrosion  is  very  severe, 
and  one  from  a  well  in  which  corrosion  is  not  troublesome.  The  water  in 
this  pool  is  produced  with  the  oil  from  the  YVestfield  lime  which  is  found 
at  an  average  depth  of  about   1-50  feet. 

In  Lawrence  County  samples  were  taken  from  two  wells  a  few  miles 
north  of  Bridgeport.  One  of  these  wells  produces  very  corrosive  water 
with  the  oil  while  the  other  well,  only  a  short  distance  away,  produces  only 
mildly  corrosive  water.  Both  wells  are  producing  from  the  Bridgeport  sand 
at  a  depth  of  about   1.000  feet. 

VALUE    OF    CHEMICAL    ANALYSES    AS    INDICES    OF    CORROSION 

The  results  of  water  analyses  are  given  in  Tables  1  and  *<!.  No  sig- 
nificant differences  appear  by  which  the  degree  of  corrosiveness  may  be 
determine  1  from  the  composition  of  the  brines,  especially  when  waters  from 
different  sands  are  compared.  For  example,  sample  A,  with  a  high  con- 
centration of  salts,  is  moderately  corrosive,  but  sample  F,  with  a  low  con- 
centration of  salts,  is  very  corrosive.  In  corrosive  waters,  the  sum  of  the 
reacting  values  of  XO;.  -|-  S()4  -f-  CI  is  frequently  greater  than  the  sum 
of  the  reacting  values  of  NH4  -4-  Na  4-  K.  This  is  true  of  many  of  the 
samples,  but  sample  F  is  an  exception.  The  fact  that  this  water  is  very 
corrosive  proves  that  the  above  relation  is  no  sure  indicator  of  corrosive- 
ness. According  to  Mills,5  corrosive  waters  are  characterized  by  a  high 
primary  salinity  generally  in  excess  of  50  per  cent,  and  a  secondary  salinity 
generally  higher  than  '^0  per  cent  but  sometimes  as  low  as  8  per  cent. 
Sample  D,  a  very  corrosive  water,  is  an  exception  to  this  classification. 
having  a  secondary  salinity  of  4.94  per  cent. 

The  value  of  a  chemical  analysis  as  an  index  of  the  corrosiveness  of 
an  oil-field  brine  seems  from  this  study  to  be  small,  except  as  it  indicates 
the  character  of  the  medium  in  which  corrosion  occurs.  Differences  between 
the  analyses  of  corrosive  and  noncorrosive  waters  are  so  inconsistent  that 
correlation  with  field  observations  of  the  corrosiveness  of  the  waters  is  im- 
possible. 

FIELD    STUDIES    OF    HYDROGEN    ION    CONCENTRATION     \M>    HYDROGEN    SULFIDE    CONTENT 

The  corrosive  properties  of  oil-field  waters  are  thought  to  be  due  in 
a  large  measure  to  the  hydrogen  sulfide  and  carbon  dioxide  content  as  dis- 
solved gases  and  to  the  presence  or  absence  of  catalysts.  Therefore,  in  addi- 
tion to  the  samples  taken  for  chemical  analysis,  field  tests  were  made  on 
water>  from  a  large  number  of  wells  scattered  throughout  the  various  pools 

•  Op.  'it.,  p.  27. 


14  ILLINOIS   PETROLEUM 

where  corrosion  is  severe  to  determine  the  amount  of  hydrogen  sulfide  dis- 
solved in  the  water,  and  to  determine  the  hydrogen  ion  concentration  which 
measures  the  'acidity  of  a  liquid.  All  of  these  tests  were  made  as  soon  as 
the  sample  was  obtained  from  the  well.  Only  those  wells  which  had  been 
pumping  continuously  for  an  hour  or  more  were  selected  for  testing.  These 
precautions  were  necessary  since  the  hydrogen  sulfide  content  of  water 
lowers  rapidly  by  chemical  decomposition  and  by  escape  of  the  gas  into 
the  atmosphere  when  the  water  is  exposed  to  the  air  or  becomes  warmer. 

RESULTS    OP    TESTS 

1  he  investigation  showed  that  the  hydrogen  sulfide  content  of  water 
indicates  its  corrosive  or  noncorrosive  qualities  only  in  a  very  general  wav. 
If  little  or  no  hydrogen  sulfide  is  present  in  the  water  there  is  probably 
no  corrosion  trouble  and  some  waters  with  relatively  high  hydrogen  sulfide 
content  are  only  mildly  corrosive.  Nearly  all  highly  corrosive  waters  have 
a  high  hydrogen  sulfide  content  hut  there  are  a  few  highly  corrosive  waters 
which  are  also  relatively  low  in  hydrogen  sulfide. 

All  tests  for  hydrogen  ion  concentration  indicate  that  the  waters  are 
only  very  slightly  acid  or  alkaline  and  in  no  test  was  the  water  sufficiently 
acid  or  alkaline  so  that  this  property  might  be  considered  an  important 
factor  in  causing  corrosive  reactions. 

Substances  that  Accelerate  Corrosion 

The  most  active  and  common  product  that  accelerates  corrosion  is  iron 
sulfide.  It  is  formed  by  the  reaction  of  the  hydrogen  sulfide  in  oil-field 
waters  with  the  iron  or  steel  equipment  in  the  wells.  Iron  sulfide  is  electro- 
negative with  respect  to  iron,  consequently  with  the  electro-positive  iron  of 
the  equipment  it  constitutes  a  minute  galvanic  battery,  and  in  the  presence 
of  water  it  greatly  stimulates  corrosion.  The  following  facts  seem  to  in- 
dicate the  importance  of  iron  sulfide  in  respect  to  corrosion. 

Many  strings  of  tubing  and  casing  are  found  to  be  corroded  deepest 
just  above  the  collars,  indicating  accelerated  corrosion  at  that  point.  This 
is  thought  to  be  due  largely  to  the  iron  sulfide  scale  which  has  lodged  upon 
the  ledges  of  the  collars,  and  to  the  susceptibility  to  corrosion  of  strained 
areas  in  the  casing  and  collars  formed  during  the  threading  of  the  collars 
and  screwing  together  of  the  casing. 

In  many  wells  the  few  lower  joints  of  tubing  or  anchor  tubing  are 
found  to  corrode  much  faster  than  the  remainder  of  the  tubing  string.  In 
some  wells  this  may  be  due  to  more  complete  immersion  but  in  others  it 
is  clearly  due  to  the  accumulation  of  iron  sulfide  around  the  tubing. 

The  rate  of  corrosion  in  many  wells  grows  progressively  more  rapid 
with  age,  but  cleaning  out  at  frequent  intervals  reduces  the  corrosion  rate. 
The  mud  and  water  removed  during  the  cleaning  is  usually  very  dark  due 


CORROSION    IN    EASTERN    ILLINOIS   Ol 


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CORROSION    IN    EASTERN    ILLINOIS   OIL  FIELDS  17 

Explanation  of  tables 

Table  1  shows  various  details  concerning  the  samples  whose  analyses  are 
given  in  Table  2. 

Table  2  gives  the  chemical  analyses  of  the  samples.  The  analyses  are  ex- 
pressed in  three  ways:  (1)  ionic  concentration,  (2)  reacting  value  in  parts  per 
million,  and   (3)  reacting  value  in  per  cent. 

The  ionic  analyses  show  the  number  of  parts  of  different  ions  present  in  a 
million  parts  of  water  by  weight.  However,  inasmuch  as  different  ions  possess  the 
ability  to  react  with  other  substances  to  different  degrees,  it  is  necessary  to  com- 
pute a  "reacting  value"  for  each  ion.  The  reaction  value  is  determined  by  multi- 
plying the  concentration  of  each  ion  by  its  "reaction  coefficient"  which  is  known 
for  the  various  ions.  Another  mode  of  expressing  reacting  values  is  in  per  cent. 
The  reacting  values  expressed  in  parts  per  million  or  per  cent  may  be  used  as  a 
basis  for  comparing  the  chemical  composition  and  activity  of  waters. 

The  salinity  or  alkalinity  of  a  water,  as  measured  by  the  ratios  of  the  strong 
and  weak  acid  and  basic  ions,  is  sometimes  used  to  indicate  the  character  of  the 
reaction  the  water  is  able  to  promote.  In  the  above  table,  primary,  secondary, 
and  salinity  express  in  per  cent  the  balance  between  the  strong  acid  ions 
and  the  alkalies,  alkali  earths  and  metals  respectively.  By  the  union  of  weak  acid 
ions  with  alkalies,  alkali  earths  and  metals,  primary,  secondary  and  alkalinity 
respectively  are  obtained. 


to  the  presence  of  particles  of  iron  sulfide.  This  also  suggests  that  the  iron 
sulfide  is  a  factor  in  accelerated  corrosion. 

Iron  sulfide  is  also  troublesome  because  it  forms  as  a  scale  on  pipe, 
tubing,  and  rods.  This  scale  becomes  loose  and  falls  to  the  bottom  of  the 
well   where  it  accumulates  in   such  quantity  as  to  interfere   with  pumping. 

Sulfur  is  also  a  substance  which  stimulates  corrosion  in  certain  forms 
of  equipment.  It  occurs  commonly  as  a  product  of  the  decomposition  of 
hydrogen  sulfide  in  water,  and  is  also  deposited  from  hydrogen  sulfide  bear- 
ing gases  when  they  become  mixed  with  the  oxygen  of  the  air,  or  when 
they  are  condensed.  Sulfur  may  be  found  coating  both  the  inside  and 
outside  of  metallic  equipment,  such  as  tubing  in  wells,  and  the  inside  of 
lead  lines  and  casing.  It  also  collects  in  rather  large  amounts  in  gas  traps 
and  gasoline  drips.  The  chief  damage  done  by  the  sulfur  is  that  it  clogs  lead 
and  vacuum  lines.  In  the  presence  of  moisture  it  undoubtedly  corrodes 
metal  in  the  same  fashion  as  does  iron  sulfide,  but  the  corrosion  produced 
by  sulfur  is  generally  secondary  in  importance  to  its  clogging. 

Effect  of  Corrosion  ox   Various  Materials 

Equipment  of  the  same  general  character  is  commonly  used  through- 
out the  oil  fields  of  the  State.  Casing  is  usually  steel  and  is  employed  in 
a  number  of  different  weights.  Some  steel  casing  containing  a  small  amount 
of  copper  is  also  use!  to  a  considerable  extent.  Lead  lines  are  of  steel, 
cast  iron,  lead-lined  steel,  and  steel  containing  a  small  per  cent  of  copper. 


IS  ILLINOIS  PETROLEUM 

Galvanized  tubing  is  used  in  very  small  amounts.  Sucker  rods  are  of  steel, 
balls  and  seats  usually  of  steel,  bronze,  or  brass,  and  working  barrels  of 
steel,  cast  iron,  wrought  iron  or  brass.  Brass  seems  to  resist  oil-field  cor- 
rosion very  well. 

In  the  corrosion  of  steel  the  surfaces  are  commonly  pitted.  The  pits 
tend  to  be  elongated  parallel  to  the  length  of  the  pipe  and  are  usually  quite 
close  together.  Often  they  are  so  elongated  that  they  appear  as  narrow 
furrows  or  flutings.  This  is  more  often  true  of  corroded  sucker  rods  than 
of  tubing  or  casing.  Ordinarily  pits  are  bordered  by  clear  uncorroded 
metal. 

Steel  equipment  containing  a  small  per  cent  of  copper  seems  to  resist 
corrosion  under  many  conditions,  but  when  hydrogen  sulfide  is  present  in 
the  waters  in  contact  with  the  casing,  the  copper  content  does  not  appear 
to  have  any  effect  upon  the  rate  of  corrosion. 

Wrought  iron  corrodes  in  much  the  same  manner  as  steel,  but  the  pits 
are  not  generally  elongated  in  any  one  direction  nor  are  there  as  many  pits 
developed  per  unit  area.  The  fewer  pits  probably  indicates  that  the  wrought 
iron  is  more  homogeneous  than  steel  in  composition  and  texture. 

Cast-iron  lead  lines  have  proved  most  economical  where  corrosion  is  bad. 
Wrought  iron  and  lead-lined  tubing  have  not  retarded  corrosion  to  such  an 
extent  that  they  effect  any  marked  saving  over  the  cheaper  steel  equipment. 
Lead-lined  tubing  has  proved  unsatisfactory  because  corrosion  occurs  at  the 
contact  of  the  lead  with  the  steel.  It  is  almost  impossible  to  obtain  a  mois- 
ture-proof contact  here.  Galvanized  tubing  is  seldom  used  because  most  of 
that  obtainable  at  the  present  time  contains  minute  holes  through  the  zinc 
coating  which  expose  the  metal  below  to  corrosion.  It  is  possible  that  with 
the  development  of  better  methods  of  applying  the  coating  of  zinc,  galvanized 
material  will  prove  quite  satisfactory. 

Corrosion  Data  by  Counties 

crawford  county 

Corrosion  of  oil-field  equipment  in  Crawford  County  is  confined  to  dis- 
tinctly localized  areas.  Those  tracts  affected  by  the  more  intense  action  are 
rarely  larger  than  a  section  in  area  and  often  are  included  within  a  single 
lease.  Generally  the  wells  in  which  corrosion  is  most  active  produce  more 
water  and  water  which  contains  more  dissolved  hydrogen  sulfide  than  the 
surrounding  wells.  Corrosion  is  most  troublesome  around  the  margins  of 
the  individual  pools. 

The  most  important  producing  sand  in  the  county  is  the  Robinson  sand 
found  at  an  average  depth  of  about  950  feet.  In  addition  there  are  a  few 
other  sands  which  are  productive  locally.  Any  or  all  of  the  sands  may  yield 
corrosive  water. 


CORROSION    l.\    EASTERN    ILLINOIS   OIL    FIELDS  19 

MAIN   CRAWFORD  COUNTY    TOOL 

On  the  Hawkins  farm  in  sec.  1,  Oblong  Township,  operated  by  the  Asso- 
ciated Producers  Company,  there  are  several  wells  between  900  and  1.000  feet 
deep  that  produce  very  corrosive  water  from  the  Robinson  sand.  In  general 
the  wells  are  pumped  straight  time  and  the  rate  of  corrosion  seems  to  be  re- 
lated to  the  amount  of  water  pumped.  Some  hydrogen  sulfide  is  present  in 
the  water.  Wrought-iron  tubing  is  used  in  the  wells  at  the  present  time, 
but  it  is  necessary  to  replace  the  lower  joints  of  the  strings  on  the  average 
of  once  every  three  weeks.  Complete  replacements  of  sucker  rods  and  steel 
lead  lines  are  made  every  two  years.  Corrosion  of  buried  lead  and  vacuum 
lines  here  is  apparently  not  due  to  soil  corrosion,  for  the  vacuum  lines  last 
much  longer  than  the  lead  lines. 

In  sec.  30,  Oblong  Township,  the  Reedy  and  Smith  lease  of  the  Mahutska 
Oil  Company,  producing  from  the  Robinson  sand,  is  troubled  little  by  cor- 
rosion except  for  a  small  amount  of  soil  corrosion  of  buried  lead  lines.  Ex- 
cept in  some  deeper  wells  on  a  nearby  lease,  extremely  corrosive  waters  are 
not  encountered  in  this  vicinity. 

Corrosion  is  quite  serious  on  the  Pearl  Dee  lease  of  the  Pure  Oil  Com- 
pany in  sec.  5,  Oblong  Township,  producing  from  the  Robinson  sand.  Cor- 
rosion is  most  active  on  that  part  of  the  (>J4-inch  casing  extending  below 
the  8-inch  casing  which  is  seated  at  about  400  feet.  The  average  life  of 
the  bottom  joints  of  the  6j4-inch  casing  is  about  two  years.  The  places  of 
maximum  corrosion  are  the  threaded  joints  and  the  areas  just  above  the 
collars,  although  the  whole  string  of  casing  is  also  quite  badly  pitted.  It  would 
seem  that  filling  the  space  between  the  6-inch  casing  and  the  wall  of  the  well 
with  a  thick  mud  might  materially  reduce  this  corrosion.  The  lead  lines  and 
sucker  rods  are  seriously  corroded,  especially  where  the  former  are  buried 
in  soil  which  has  become  impregnated  with  sulfur  and  various  salts  by  oil 
and  water  refuse  from  receiving  tanks. 

In  sec.  10.  Oblong  Township,  the  J.  W.  Shire  lease  of  the  Mahutska  Oil 
Company  produces  oil  with  practically  no  water  from  the  Robinson  sand. 
Corrosion  gives  very  little  trouble  here,  but  occasionally  lead  lines  require 
replacement. 

The  C.  B.  Walker  lease  of  the  Ohio  Oil  Company  in  sec.  27,  Martin 
Township,  produces  oil  without  water  from  the  Robinson  sand.  There  is 
no  corrosion  on  this  lease  or  in  this  vicinity,  which  shows  that  the  salt  water 
and  not  the  oil  causes  corrosion  in  the  oil  fields. 

On  the  G.  W.  Jones  lease  of  the  Ohio  Oil  Company  in  sec.  35,  Martin 
Township,  the  waters  are  quite  corrosive.  The  wells  were  all  originally 
drilled  through  the  Robinson  sand  into  water  and  consequently  they  must 
now  be  pumped  straight  time  at  the  rate  of  20  barrels  of  fluid  per  hour. 
The  waters  contain  dissolved  hydrogen  sulfide.  Corrosion  of  the  6^4-inch 
casing  is  moderately  severe  and  is  most  active  about  midway  of   the  well. 


20  ILLINOIS  PETROLEUM 

Ordinary  steel  lead  lines  last  about  three  months  for  wells  most  subject  to 
corrosion,  but  some  of  the  lead-lined  pipe  has  been  in  use  for  over  two 
years.  Steel  tubing  lasts  about  six  months ;  galvanized  tubing  about  twice 
that  long.  Sucker  rods  are  commonly  replaced  when  the  tubing  is  changed. 
Of  interest  in  connection  with  corrosion  in  these  wells  is  the  fact  that  anchor 
tubing  is  eaten  through  at  a  more  rapid  rate  than  the  tubing  above  the 
working  barrel,  probably  because  the  water  acts  on  it  from  the  outside  as 
well  as  the  inside. 

BELLAIR  POOL 

Corrosion  is  quite  severe  on  the  Susanne  Smith  lease  of  the  Ohio  Oil 
Company  in  sec.  11,  Licking  Township.  Production  is  obtained  from  two 
sands,  the  upper  is  probably  the  Robinson  sand  and  the  lower  is  one  of  the 
sands  of  the  Chester  series.  The  water  from  the  lower  of  the  two  sands 
is  the  more  corrosive.  A  comparatively  large  amount  of  water  is  pumped 
with  the  oil.  It  is  commonly  necessary  to  replace  steel  lead  lines,  tubing, 
and  sucker  rods  about  every  year.  Many  of  the  lead  lines  are  of  cast  iron 
but  even  these,  where  corrosion  is  the  most  active,  must  be  replaced  within 
a  period  of  two  years.  Most  of  the  wells  that  produce  from  the  lower  sand 
in  this  vicinity  are  also  troubled  with  corrosion. 

PARKER  POOL 

Probably  the  most  intense  and  destructive  corrosion  in  the  county  occurs 
in  the  vicinity  of  the  Parker  lease  in  Honey  Creek  Township  in  what  is  com- 
monly called  the  Parker  pool.  A  great  deal  of  water,  high  in  hydrogen  sul- 
fide, is  produced  with  the  oil  from  the  Robinson  sand.  Many  of  the  wells 
are  pumped  straight  time.  Corrosion  is  particularly  bad  on  sucker  rods  and 
the  lower  joints  of  tubing  and  casing.  The  action  of  corrosion  upon  casing- 
seems  to  be  from  the  outside  inward,  and  below  the  seat  of  the  8-inch 
casing  the  634-inch  pipe  shows  the  effects  of  corrosion  to  a  greater  degree 
than  elsewhere,  particularly  just  above  the  collars.  This  corrosion  would 
probably  be  greatly  lessened  by  the  introduction  of  a  thick  mud  between  the 
6%-inch  casing  and  the  wall  of  the  well.  Cast-iron  tubing  is  used  in  at 
least  one  well,  and  chain-steel  sucker  rods  in  nearly  all  wells.  The  iead 
lines  are  of  cast  iron. 

BIRDS   POOL 

In  the  Birds  pool,  located  in  Lawrence  and  Crawford  counties  and  pro- 
ducing from  the  Robinson  sand,  corrosion  is  not  a  serious  factor.  It  is 
confined  mostly  to  working  parts  such  as  the  balls  and  seats,  and  working 
barrels. 

FLAT  ROCK  POOL 

The  conditions  in  the  Flat  Rock  pool  in  Honey  Creek  Township  are 
very  similar  to  those  in  the  Parker  pool,  but  the  volume  of  water  pumped 
from  most  of  the  wells  is  less  than  that  pumped  from  the  wells  in  Parker 


CORROSION    IX   EASTERN    ILLINOIS  OIL  FIELDS  21 

pool,  consequently  the-  corrosion  is  slower.  Hydrogen  sulfide  is  present  in 
relatively  large  amounts  in  the  gas  and  water  pumped  with  the  oil.  Produc- 
tion  is    from   the   Rohinson   sand. 

LAWRENCE    COUNTY 

The  oil  fields  of  Lawrence  County  have  no  serious  corrosion  problems 
except  for  an  area  north  of  Bridgeport,  near  Millerville.  There  are  five 
major  producing  sands  in  this  area  of  which  the  Bridgeport  sand  is  the 
youngest  and  most  shallow,  and  carries  the  corrosive  water.  In  general 
where  the  largest  volumes  of  water  are  pumped  the  hydrogen  sulfide  con- 
tent of  the  water  is  highest  and  corrosion  is  most  active. 

CLARK    COUNTY 

Oil  well  equipment  in  Clark  County  suffers  more  from  corrosion 
than  any  other  of  the  counties  mentioned.  The  Siggins  pool,  northwest 
of  Casey,  is  the  only  producing  area  in  the  county  not  seriously  affected, 
and  the  condition  here  is  probably  due  to  the  small  amount  of  water  pro- 
duced with  the  oil.  In  general,  however,  tubing,  sucker  rods,  casing,  and 
lead  lines  are  all  destroyed  in  a  relatively  short  time.  Corrosion  is  worst 
in  the  north  part  of  the  county.  Various  kinds  of  equipment  such  as  cop- 
peroid  tubing  and  casing,  cast-iron  tubing  and  lead  lines,  wrought-iron 
tubing,  and  lead-lined  tubing  have  been  tried  in  an  attempt  to  increase 
the  length  of  time  between  replacements,  but  only  cast  iron  has  been  found 
to  resist  corrosion  for  any  length  of  time.  It  has  been  used  in  tubing  and 
lead  lines. 

WESTFIELD  POOL 

The  Parker  Township  or  Westfield  pool  probably  produces  with  the 
oil  the  most  corrosive  water  in  the  State.  Many  of  the  gas  lines,  lead 
lines,  and  vacuum  lines  in  this  pool  become  choked  with  a  scale  high  in 
sulfur,  and  this  necessitates  replacing  or  cleaning  the  lines  at  rather  fre- 
quent  intervals. 

The  gas  from  this  pool  has  a  higher  hydrogen  sulfide  content  than 
any  other  produced  in  Illinois,  and  for  that  reason  very  little  of  it  is  run 
through  compression  or  absorption  plants  to  extract  gasoline. 

The  corrosive  waters  are  produced  with  the  oil  from  the  so  called 
"Westfield"  lime.  Wells  producing  only  from  the  "Trenton"  are  not 
troubled  with  corrosion.  Water  from  the  Niagaran  is  said  to  be  very  cor- 
rosive. 

CASEY    TOWNS  II II',    JOHNSON    TOWNSHIP,    AND    MARTINSVILLE    POOLS 

Corrosive  waters  are  also  found  in  the  Casey  Township  pool,  the  |ohn- 
son  Township  pool,  and  the  .Martinsville  pool.  In  Johnson  and  Casey 
townships  the  production  comes  mostly  from  one  sand,  the  Casev  sand, 
which  yields  considerable  water  with  some  dissolved  hydrogen  sulfide. 


22  ILLINOIS  PETROLEUM 

In  the  Martinsville  pool  production  is  principally  from  two  sands, 
the  Carper  and  the  Niagaran.  Nearly  all  of  the  wells  produce  from  the 
two  sands  at  the  same  time.  For  two  years  or  more  nearly  all  of  the  wells 
in  this  pool  produced  only  from  the  Carper  sand,  and  no  trouble  from  cor- 
rosion was  encountered  in  any  of  the  wells  until  they  had  been  deepened 
to  the  Niagaran.  Soon  after  this  it  was  noticed  that  tubing  and  rods  re- 
quired replacement  more  often  than  before.  Unfortunately,  most  of  the 
water,  and  oil  too,  are  produced  from  this  formation  ,so  that  plugging  it 
off  would  both  prevent  rapid  corrosion  and  take  away  the  best  part  of  the 
oil  production. 


1,      (87432—1,500) 


